By , Monday, Jun 4, 2012, 12:00 PM

St. Peter's Basilica, one of Rome's most beautiful churches. Make sure you adhere to the modest dress code—both men and women are required to enter with their shoulders and knees covered out of respect.

(Courtesy Kaeli Conforti)

Crowds fill St. Peter's Square on a sunny Sunday afternoon in Rome.

(Courtesy Kaeli Conforti)

The Swiss Guard outside St. Peter's Basilica in Rome, Italy.

(Courtesy Kaeli Conforti)

The Vatican Museums are free to enter on the last Sunday of the month between 9 a.m. and 12:30 p.m., and it's worth braving the crowds to see the Sistine Chapel.

(Courtesy Kaeli Conforti)

Rome's beautiful yet imposing Castel Sant' Angelo.

(Courtesy Kaeli Conforti)

The Ponte Sant'Angelo bridge lets Bernini's angel sculptures lead you back into the city center.